Journal of Agriculture and Livestock Farming

ABSTRACT

A study was done to estimate the uncertainty of waste analysis by XRD technique on powder samples. The XRD technique is important for identifying crystalline phases and inorganic compounds to give information about hazardousness on unknown wastes. No reference materials or proficiency tests are available for these sometimes very complex and heterogeneous matrices. The present study was done on a real sample with a metrological approach. The matrix complexity in the considered sample, even after grinding, is increased by the fact that there is a fibrous fraction and a nonfibrous powdery fraction mixed together. Accuracy was checked by analysis with other techniques and at other laboratories. The results showed that external calibration with single pure standard is prone to large errors compared with the use of multi-level external calibration. The approach that best accounts for matrix complexities is however the method of standard additions. The level of uncertainty determined was within ±50% as the expanded uncertainty (k~2, conf. level 95%).

KEYWORDS

1. Wastes
2. X-Ray diraction
3. Uncertainty